Intersection Points & Finding Unknown Variable

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Discussion Overview

The discussion revolves around the conditions under which a line intersects a parabola at two distinct points. Participants explore the mathematical relationships between the equations of the line and the parabola, focusing on the implications of the discriminant in determining the nature of the intersection. The scope includes mathematical reasoning and problem-solving related to algebraic expressions.

Discussion Character

  • Mathematical reasoning
  • Debate/contested

Main Points Raised

  • One participant presents the equations of the line and parabola and attempts to set them equal to find intersection points, leading to the equation 0 = x^2 - 2 - k.
  • Another participant suggests that the discriminant should be used to analyze the conditions for distinct intersection points, but expresses uncertainty about the correctness of their approach.
  • There is a correction regarding the equation of the parabola, with one participant noting a mistake in the original formulation and clarifying that it should include the x^2 term.
  • Further elaboration is provided on the implications of different values of k, indicating that for k < -2, there are no real solutions, while for k > -2, real solutions exist, and k = -2 results in a single intersection point.

Areas of Agreement / Disagreement

Participants express differing views on the correct application of the discriminant and the implications of the values of k. There is no consensus on the final interpretation of the conditions for intersection points.

Contextual Notes

Participants rely on the discriminant to analyze the quadratic equation formed by equating the line and parabola, but there are unresolved aspects regarding the correct application and interpretation of the results based on the value of k.

confusedatmath
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The line with equation y = x + k, where k is a real number, intersects the parabola with equation y = x^2 + x − 2 in two distinct points if

I first made the equations equal each other

x + k = x^2 + x − 2
0 = x^2 -2 -k

From here i thought you use the discriminate a=1 b=o c=-2-k

but this isn't right, because the answer to choose from

k < − 2

k > − 2

k = − 2

k < 2

k ≠ 2
 
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confusedatmath said:
The line with equation y = x + k, where k is a real number, intersects the parabola with equation y = + x − 2 in two distinct points if

I first made the equations equal each other

x + k = + x − 2
0 = -2 -k

From here i thought you use the discriminate a=1 b=o c=-2-k

but this isn't right, because the answer to choose from

k < − 2

k > − 2

k = − 2

k < 2

k ≠ 2

Hello.

Check the wording of the question. The parable, need that 'x' is not high to the power 1. (would be a straight line)

Regards.
 
mente oscura said:
Hello.

Check the wording of the question. The parable, need that 'x' is not high to the power 1. (would be a straight line)

Regards.
i fixed it :p read again, it was a mistake i forgot the x^2
 
confusedatmath said:
The line with equation y = x + k, where k is a real number, intersects the parabola with equation y = x^2 + x − 2 in two distinct points if

I first made the equations equal each other

x + k = x^2 + x − 2
0 = x^2 -2 -k

From here i thought you use the discriminate a=1 b=o c=-2-k

but this isn't right, because the answer to choose from

k < − 2

k > − 2

k = − 2

k < 2

k ≠ 2

Now yes.

0=x^2-2-k

x^2=k+2

x=\pm{} \sqrt{k+2}

1º) k&lt;-2 \rightarrow{}x \cancel{\in}{R}

2º) k&gt;-2 \rightarrow{}x \in{R}

3º) k=-2 \rightarrow{}x=0, only a breakpoint.

Regards.
 

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